Combined telephonic and telegraphic system.



E. R. GILL. COMBINED TELEPHONIC AND TELEGRAPHIG SYSTEM.

APPLICATION FILED AUG. 5,1907.

' Patented Mar. 26, 1912 m1 TED sTA'i srATEnr OFFICE.

EDWIN R. GILL, 0F YO'NKERS, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, TOHOWARD E. MERRELL, OF NEW YORK, N. Y., AND ORLO J. HAMLIN, OFSMETHLEORT',

PENNSYLVANIA.

To all whom it may concern:

Be it known that I, EDWIN R. GILL, a citizen of the United States,residing in the city of Yonkers, county of VVestchester, and State ofNew York, have invented a certain new and useful Improvement in CombinedTelephonic and Telegraphic Systems, 'of which the following'is aspecification.

This invention has especial relation to an improved system whereby any,number of points along a telegraph line of indefinite length can bebrought -rapidly into telephonic communication with any other, and

in such a manner as to cause no disturbance or annoyance to stationsalong the line not intended to be reached at the moment.

In railway practice particularly it often becomes important for a traindespatcher,

for instance, to be able to reach some employee upon the hue andconverse with him,

'so that conditions at or near the point where. the employee is locatedmay be ascertained.

and orders givenaccordingly. Again many occasions arise when it becomesimportant for an employee somewhere along the line to communicate atonce with headquarters un= de'r circumstances permitting rapidconversat-ion. been sought to establish a' telephonic system extendingparallel to'the railway lines and terminating in the despatchers office,but the mode of construction and arrangement of such systems hashitherto been such as to I involve such a serious dissipation ofelectric energy, that, in practice, it has not been found possible touse more than a very limited number of instruments and the scope ofusefulnessof telephones so used is therefore very restricted.

By the use of my present invention the number of instruments which maybe used is without limit and at the same time conversation is perfectlyclear. I accomplish this by providing at intervals along a telegraphline'.

on. At the same time, the relays at these stations, which are as' usualin series on the telegraph line, areprovided. with suitable bridgingmeans, such, as condensers and h gh nonnductive resistances, which,wh1le To accom )lish this uroose it has' COMBINED TELEPHONIG ANDTELEGRAPHIC SYSTEM.

' Specification of Letters Patent. Patented Mar. 26,1912. Applicationfiled August 5, 1907. Serial m. 387,621.

afi'ording a pat h around said'relays for the 1 undulatory telephoniccurrents, do not divert the telegraphingcurrent from said relays. Eachstation is moreover supplied with a selective calling apparatus operatedpreferably by the relays, whereby any one station may be calledwithoutdisturbing any used afford such a serious obstacle to extend- Ted use of telephones.

An illustrative embodiment of-my invention is shown in diagram in theaccompanying drawing which represents the equipment of atraindespatchers office and two distant statlons, united by a singletelegraph line provided with my invention.

.The despatchers telegraphing and calling key is shown at 1, and near itis indicated the telephonic apparatus at the despatchers The maintelegraphic line is indiofiice. cated at 2 and the main line battery at3. ll hereVer desired along the line are placed relayset, in series withthe main line and with each other and each relay 4 through an,

insulated back stop controls circuit through a local'battery 5 and theoperative parts of a selective circuitcloser 6, whose terminals are at 7andS. These devices act in any well known manner to close the circuit ofa call bell 9 or equivalent device through terthey are so constructed ina well known manner that themormal use of the main telegraph w re 2 forordinarytelegraphing is not interfered with by and does not itselfinterfere with operation of the selective devices,

At each station is placed a telephonic'outlit, the various outfits beingin multiple are;

and, in the form shown this arrangement is produced by grounding eachtelephoneon It is to be understood that, although only three selectivecircuitclosers are shown/with their associated apparatus, any desirednumber' may be used 0 the same circuitfi In the preferrecharrangement:sh'own each,-

one side, while. itsother side is connected 41 'Wlilll the telegraphwire 2.

relay 4 is bridged by non-inductive coils of conversation circuit 1Sclosed from the telereceiver 7 and by the ground back to the line. 7

li ear the grounded ends of the main line choke coils are introduced toproperly conthe telephonic currents.

' refer-to keep the telephone batteries nor lly out of circuit and tobring them into lrcuit automatically when the receiver is lifted. orthis purpose I provide an insulated metal blade 20 on the rearof thelever 15, which blade is electrically connected shown with thetransmitter 21.

The opposite side of this transmitter is connected to one pole of thelocal battery 22,

the other pole of which is connected to the primary coil 23 of thetelephone transtoriner. The remaining terminal of said primary 001i .isconnected to theconducting spring contact :24: whereby circuit is closedthrough the battery, transmitter and transformer primar-y Whenthe lever15 is tilted'by the spring 16 on removal of the receiver.

In using the apparatus described, the key 1 is employed in. the usualmanner to operate the particular selective circuit closer 6 at thestation to be called. This causes the proper hell 9 or equivalent deviceto ring so as to attract the attention of the person called,1whothereupon lifts the receiver at his station, thus connecting histelephonic outfit With. the telegraphic line. The person callingphavingin the meantime raised his own receiver, conversation can be carried onbetween the two. As soon as the conversa tion terminates, both receiversare hung up and bothtelephonic outfits are once more out of connectionwith the line.

It isjto be understood that my inventiop covers any arrangement, wherebyelectrical connection between the telegraphic line and each telephonicoutfit is normally broken and whereby this connection is produced atwill when it is desired to use the telephone in high resistance 12, inmultiple arc with cone through the branch Wire 18 of conversation. Thearrangement above described has a decidedadvantage over multi le arctelephonic systems which include ca ling means in each telephonicbranch, in thatthe dispersion of energy caused by the presence of thesecalling devices is avoided and it is therefore possible to greatlyincrease thenumber of telephones which can be used along a. singletelegraphic line,

Whatl claim is- I 1. A telegraphic line in combination with a number ofselectively operated signaling" devices at intervals along said line,phonic outfit adjacent to each signaling device normally disconnectedfrom the telegraphic line, means for opcratively coinnct mg eachtelephonic outfit totlie' telegraphic line so that whentwo or more ofsaid outfits multaneously connecting said receiver and transformersecondary to said telegraphic line and-closing the local transmittercircuit, and means for operating said selectively operatcd signalingdevices over said telegraphic line, said last named means includ ing acircuit independent of all of said telephonic circuits, substantially asdescribed.

3. A telegraphic line, a number of selectively operated signalingdevices at intervals along said line, relays in series along said linefor controlling said selectively op erated signals, condensers in shuntaround each of said relays, a complete local telephonic outfit adjacentto eacn signaling device and normally disconnected from the telegraphicline and means for operatively connecting each telephonic outfit to thetelegraphic line so that when two or more of said outfits are soconnected they will be in,

' M. A. BUTLER.

